Audio Research I/55 Integrated Amplifier

The I/55 integrated amplifier builds on the I/70’s advancements while maintaining the compact size and output of the I/50. Its all-tube design uses matched 6550 output tubes and 6922 input tubes to deliver the musicality, bass depth and dynamic expression Audio Research is known for. New features include auto-bias, a more capable active preamp section, headphone output driven by the output tubes and stereo preamp outputs. Optional DAC and phono modules add high-resolution digital and analog flexibility, including USB, Bluetooth, balanced XLR inputs and adjustable MC/MM phono settings. The I/55 combines versatility, refinement, and classic tube performance in a compact package.

Colors: All I/55 units come with black power button; knobs can be black or two tone. Chassis parts available in
black and silver. Top plate color options include: black, blue, gold, red, silver, or white. Color must be chosen at time of order; top plates are not interchangeable.

Technical Specifications:

Power Output: 50 watts continuous from 20Hz to 20kHz. 1kHz total harmonic distortion typically 1% per channel, below 0.1% at 1 watt (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not critical)

Power Bandwidth: (-3dB points) 10Hz to 22kHz

Frequency Response: (-3dB points at 1 watt) 7Hz to 30kHz

Input Sensitivity: 1.25V RMS for rated output

Input Impedance: 100K ohms Balanced, 48K ohms Single Ended

Output Polarity: Non-inverting. Balanced input pin 2+ (IEC-268)

Input Impedance: 100K ohms Balanced, 50K ohms SE ; 8 Inputs – 4 balanced, 4 single-ended

Output Taps: 8 ohms, 4 ohms

Power Requirements: 105-130VAC 60Hz (210-250VAC 50Hz) 252 watts at rated output

Tube Required: 2 matched pairs 6550WE; 3 x 6922 (1 input, 2 driver)

Dimensions:

Width: 16.5” (42 cm)

Height: 7.25” (18 cm)

Depth: 13.5” (34 cm)

Weight: 40 lbs (18.1 kg); 51 lbs (23.1kg) shipping weight